The University of Richmond grieved Sunday even as its graduation ceremony went on after two of the school's key athletic figures died in a hot-air balloon accident Friday.

The university confirmed that associate head women's basketball coach Ginny Doyle and Natalie Lewis, head of women's basketball operations, were killed when the balloon caught fire and crashed Friday night in Virginia's Caroline County.

Balloon pilot Daniel Kirk, a retired Army lieutenant colonel who served in the military for 37 years, also died. Kirk had more than 30 years of ballooning experience, according to his father.

Searchers found the remains of the last victim at 11 a.m. Sunday about 100 yards from where a second body was found Saturday.

The finding came just hours before the University of Richmond's 2014 graduation ceremony.

"As alumnae, classmates, and colleagues — and as invaluable and devoted mentors for our student-athletes — Ginny and Natalie have been beloved members of our community," President Edward Ayers said in a written statement. "Their leadership and friendship will endure in the lives of so many."

Doyle, 44, earned all-conference honors twice as a Richmond basketball player and held the NCAA women's record with 66 consecutive free throws until 2011. Before becoming associate coach at Richmond, she was an assistant college coach at Rhode Island and East Carolina.

"Words cannot begin to express our sorrow," said Keith Gill, director of athletics. "We are all stunned by the tragic news. Our thoughts and prayers go out to their loved ones."

A spokeswoman for Lewis' family, Julie Snyder, called Lewis "an amazing person and a strong person, an athlete engaged to be married."

Lewis, 24, swam for the University of Richmond and was a two-time team captain. After graduating in 2011, she was hired to direct the school's women's basketball operations, according to The Buffalo News. Lewis had been a star swimmer at Buffalo's Nardin Academy before being awarded an athletic scholarship at Richmond. Scott Vanderzell, her former coach with the Tonawanda Titans swimming program, said Lewis "was one of the elite swimmers to come out of western New York.

The incident happened after several hot-air balloons took off from Meadow Event Park, about 25 miles north of Richmond, as part of a preview of the Mid-Atlantic Balloon Festival on Saturday. Two balloons landed safely, but as Kirk's balloon attempted to land, it struck a power line and burst into flames.

"It contacted power lines, caught on fire and crashed in a wooded area," said Peter Knudson, a spokesman for the National Transportation Safety Board.

An air-safety investigator with the National Transportation Safety Board said a preliminary report on the crash would be released in 10 days. Heidi Moats of the NTSB said investigators were seeking records on the balloon and the pilot.

Steve Hoffmann, who said he built the Eagle balloon that Kirk was piloting in Doswell and taught him to fly, called Kirk "one of the nicest guys in the world" and a consummate professional.

"He was not a hot dog, not a risk taker," Hoffmann said. "It's so unbelievable that everyone's in shock."

Hoffmann said he was shocked when he learned Kirk was the pilot of the balloon that crashed.

"He was very careful," Hoffmann said. "Something definitely went wrong. This is not the kind of flying Dan would do."

Twenty balloonists from the Mid-Atlantic region had been set to participate in the weekend event, said Greg Hicks, a spokesman for Meadow Event Park.

"It's just a shocking situation for everyone," Hicks said.

Based on witness accounts, Kirk tried to regain control of the balloon and manage the fire. Witnesses recall hearing an explosion, and the fire continued to spread. The basket and the balloon then separated.

"As soon as we looked up, the thing blew up right there," witness Debra Ferguson told The Free Lance-Star of Fredericksburg, Va. "All I heard was, 'Oh my God, Oh my God,' and all you saw was the top of the balloon still flying, but all of the basket was gone. All of the flames just disappeared. ... It was like a match — poof — and then it was gone."

Carrie Hager-Bradley said she saw the balloon in flames on her way home from the grocery store and heard people yelling, according to WWBT-TV.

"They were just screaming for anybody to help them," the station quoted her as saying. "'Help me, help me, sweet Jesus, help. I'm going to die. Oh my God, I'm going to die,'" Hager-Bradley said she heard one person screaming.

There have been hundreds of hot-air balloon accidents in the U.S. and overseas, according to records from the National Transportation Safety Board.

The majority aren't fatal. However, in February 2013, at least 19 people died after a hot-air balloon flying over Luxor, Egypt's city of pyramids, caught fire and plunged down into a sugar cane field.

"Ballooning is normally a very safe, routine activity," Glen Moyer, editor of Ballooning magazine, the in-house publication of the 2,200-member Balloon Federation of America, said after the Luxor crash. "It's an activity that thousands of people participate in all the time and do so safely."

Troy Bradley, former president of the Balloon Federation of America, said most serious balloon accidents — including fires, electrocution and baskets becoming severed — happen after hitting power lines. Most of the time it's due to pilot error, he said.

In the U.S., hot-air balloons — which use propane gas to heat the air that rises into the balloon and lifts it — are built to standards approved by the FAA, Moyer said. In order to get a license, pilots must demonstrate a proficiency in emergency skills as well as the ability to operate the balloon. They must go through a flight review every two years, he said.